1) auto bids on ebay are not legally binding
2) the buyer admitted he knew that was not the intended selling price of the car
3) the buyer expected to be able to profit from the dealers mistake. There's no reason for them to allow a customer to do this.

Dealer is in the right, 100%, if i owned a dealership i would've said no too. He didn't "BUY" the bentley. He didn't sign anything or recieve anything signed that he owned it or was buying it.